Conventionally, when printing data to be printed (means “print data” from here) showing a document to be printed (such as an Extensible Markup Language (XML) document contains an image) using a printer connected to a personal computer (abbreviated as “PC” from here), printing is performed by representing print data using a control language (such as Page Description Language) for a PC, then transforming it to an object image (abbreviated as “OI” from here) with the descriptions of the image data, further transforming the transformed OI to a print image data, and processing the print image data using a printer.
FIG. 1 is a diagram showing the process of making the print image data from a file represented using a control language in the case of the above-mentioned conventional printing. As shown in FIG. 1, first, a file to which information on a page written in a control language is added for all the print data, next, page by page data necessary for printing in the file is sent. The printer prints based on the received data. In this case, all the data of text data, image data and the like in the document are written in a control language.
Conventional printers are made without considering the case where printing is performed by connecting to a device (such as an set top box (STB) of a digital television) that does not have the function for transforming print data to a file written in a control language unlike a PC while they have the function for receiving data sent from outside. More specifically, a screen display of a digital broadcasting program displayed on a digital television screen comprises a plurality of files, that is, a BML file contains the component information of the screen display, a JPEG (Joint Photographic Experts Group being an image compression standard) file and an AAC (Advanced Audio Coding being an audio compression standard) file which are components of a display screen and the like, which means that a printer must receive data (such as a BML file or a JPEG file) that is sent from an STB and the like as it is before transforming the data to a file written in a control language, and perform transformation processing that is performed conventionally by a PC when performing printing by connecting a printer to a device such as this distal television. Therefore, the processing load necessary for such as a transformation processing in the printer increases and the needed memory capacity at the time of printing also increases, which results in a drawback of high cost and the like.
Therefore, this present invention is made considering the above-mentioned problems and its aim is providing a printing apparatus, a content output apparatus and a printing system operable to transform a BML file, a JPEG file or the like into a file written in a control language while the processing is conventionally performed by a PC, and further, transform the file written in a control language into an OI more efficiently while the processing is conventionally performed by a printer using a smaller memory capacity.